Method and system for switching modes of a robotic system

ABSTRACT

A medical robotic system includes articulated instruments extending out of a distal end of an entry guide. Prior to pivoting the entry guide to re-orient it and the instruments, the instruments are moved in tandem back towards the entry guide after a delay. Haptic cues and velocity limits are provided to assist the operator in the retraction of the instruments. After retraction, the entry guide may then be pivoted without concern that the instruments will harm patient anatomy. The movement of the instruments in tandem back towards the entry guide may also occur through coupled control modes while the entry guide is held in a fixed position and orientation.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part to U.S. application Ser. No. 13/294,403, filed Nov. 11, 2011, now U.S. Pat. No. 9,138,129, which is incorporated herein by reference.

U.S. application Ser. No. 13/294,403 is a continuation-in-part to U.S. application Ser. No. 12/780,071 entitled “Medical Robotic System with Coupled Control Modes,” filed May 14, 2010, now U.S. Pat. No. 8,620,473, which is a continuation-in-part to U.S. application Ser. No. 11/762,200 entitled “Minimally Invasive Surgical System,” filed Jun. 13, 2007, now U.S. Pat. No. 7,725,214, each of which is incorporated herein by reference.

U.S. application Ser. No. 13/294,403 is also a continuation-in-part to U.S. application Ser. No. 12/489,566 entitled “Medical Robotic System Providing an Auxiliary View Including Range of Motion Limitations for Articulatable Instruments Extending Out of a Distal End of an Entry Guide,” filed Nov. 5, 2009, now U.S. Pat. No. 9,089,256, which is incorporated herein by reference.

U.S. application Ser. No. 13/294,403 is also a continuation-in-part to U.S. application Ser. No. 12/613,328 entitled “Controller Assisted Reconfiguration of an Articulated Instrument During Movement Into and Out of an Entry Guide,” filed Nov. 5, 2009, now U.S. Pat. No. 9,084,623, which is a continuation-in-part to U.S. application Ser. No. 12/541,913 entitled “Smooth Control of an Articulated Instrument Across Areas with Different Work Space Conditions,” filed Aug. 15, 2009, now U.S. Pat. No. 8,903,546, each of which is incorporated herein by reference.

FIELD OF THE INVENTION

The present invention generally relates to medical robotic systems and in particular, to a method and system for moving a plurality of articulated instruments in tandem back towards an entry guide out of which the plurality of articulated instruments extend.

BACKGROUND OF THE INVENTION

Medical robotic systems such as teleoperative systems used in performing minimally invasive surgical procedures offer many benefits over traditional open surgery techniques, including less pain, shorter hospital stays, quicker return to normal activities, minimal scarring, reduced recovery time, and less injury to tissue. Consequently, demand for such medical robotic systems is strong and growing.

One example of such a medical robotic system is the DA VINCI® Surgical System from Intuitive Surgical, Inc., of Sunnyvale, Calif., which is a minimally invasive robotic surgical system. The DA VINCI® Surgical System has a number of robotic arms that move attached medical devices, such as an image capturing device and Intuitive Surgical's proprietary ENDOWRIST® articulated surgical instruments, in response to movement of input devices operated by a Surgeon viewing images captured by the image capturing device of a surgical site. Each of the medical devices is inserted through its own minimally invasive incision into the Patient and positioned to perform a medical procedure at the surgical site. The incisions are placed about the Patient's body so that the surgical instruments may be used to cooperatively perform the medical procedure and the image capturing device may view it.

To perform certain medical procedures, however, it may be advantageous to use a single aperture, such as a minimally invasive incision or a natural body orifice, to enter a Patient to perform a medical procedure. For example, an entry guide (also referred to as a “guide tube”) may first be inserted, positioned, and held in place in the entry aperture. Instruments such as an articulated camera and a plurality of articulated surgical tools, which are used to perform the medical procedure, may then be inserted into a proximal end of the entry guide so as to extend out of its distal end. Thus, the entry guide provides a single entry aperture for multiple instruments while keeping the instruments bundled together as it guides them toward the work site.

U.S. 2009/0326318 A1 describes visual cues that aid an operator in repositioning the orientation of an entry guide so that the ranges of motion of articulated instruments extending out of its distal end may be optimized. U.S. 2011/0040305 A1 describes controller assisted reconfiguration of an articulated instrument during its movement into and out of an entry guide. U.S. 2011/0201883 A1 describes an entry guide for multiple instruments in a single port surgical system. U.S. 2008/0071288 A1 describes minimally invasive surgery guide tubes, articulated instruments extendable out of the guide tubes, and controllers for controlling movements of the guide tubes and instruments.

In addition to optimizing the ranges of motion of the articulated instruments, it may be necessary to change the orientation of the entry guide and consequently articulated instruments disposed therein so that one or more of the articulated instruments may reach or otherwise access a location within a Patient where a medical procedure is to be performed. When changing the orientation of the entry guide, however, care should be taken to ensure that the articulated instruments extending out of its distal end do not strike and harm surrounding tissue or other anatomical structures of the Patient. Also, haptic cues may be provided to assist a Surgeon during the entry guide re-orientation process.

OBJECTS AND SUMMARY

Accordingly, one object of one or more aspects of the present invention is a medical robotic system and method implemented therein that facilitates changing the orientation of an entry guide, through which articulated instruments are extendable, in a manner that avoids harming a Patient.

Another object of one or more aspects of the present invention is a medical robotic system and method implemented therein that facilitates changing the orientation of an entry guide, through which articulated instruments are extendable, in a quick and efficient manner that minimizes the steps to be performed by an operator of the medical robotic system.

Still another object of one or more aspects of the present invention is a medical robotic system and method implemented therein that facilitates operator controlled retraction of one or more articulated instruments into an entry guide as part of the process of re-orienting the entry guide or in other applications in which such controlled retraction is useful.

Yet another object of one or more aspects of the present invention is a medical robotic system and method implemented therein for retracting a plurality of articulated instruments in tandem back towards an entry guide out of which the plurality of articulated instruments extend.

These and additional objects are accomplished by the various aspects of the present invention, wherein briefly stated, one aspect is a method for moving a plurality of articulated instruments in tandem back towards an entry guide, the method comprising: causing the plurality of articulated instruments to assume retraction configurations after a delay which follows receiving one or more commands to move the plurality of articulated instruments in tandem back towards the entry guide.

Another aspect is a robotic system comprising: at least one input device; an entry guide; a plurality of articulated instruments extending out of a distal end of the entry guide; a plurality of instrument manipulators for manipulating corresponding ones of the plurality of articulated instruments; and a processor adapted to: command the plurality of instrument manipulators to manipulate the plurality of articulated instruments so as to assume retraction configurations after a delay which follows receiving one or more commands received from the at least one input device to move the plurality of articulated instruments in tandem back towards the entry guide.

Another aspect is a method for switching modes of a robotic system, the method comprising: receiving an indication that a mode change has been initiated; providing a haptic detent on an input device after a delay following the receiving of the indication that the mode change has been initiated; and changing an operating mode of a robotic system after the input device has been manipulated past the haptic detent.

Still another aspect is a robotic system comprising: an input device; and a processor programmed to receive an indication that a mode change has been initiated, cause a haptic detent to be provided on an input device after a delay following the receiving of the indication that a mode change has been initiated, and change an operating mode of the robotic system after the input device has been manipulated past the haptic detent.

Additional objects, features and advantages of the various aspects of the present invention will become apparent from the following description of its preferred embodiment, which description should be taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a schematic view of a medical robotic system utilizing aspects of the present invention.

FIGS. 2 and 3 respectively illustrate alternative embodiments of a Patient side support system useful in a medical robotic system utilizing aspects of the present invention.

FIG. 4 illustrates reference frames and degrees-of-freedom associated with manipulation of an entry guide in a medical robotic system utilizing aspects of the present invention.

FIG. 5 illustrates a block diagram of components of an entry guide manipulator for manipulating an entry guide in a medical robotic system utilizing aspects of the present invention.

FIG. 6 illustrates a front view of a Surgeon console useful in a medical robotic system utilizing aspects of the present invention.

FIG. 7 illustrates a perspective view of a distal end of an entry guide with articulated instruments extending out of it in a medical robotic system utilizing aspects of the present invention.

FIG. 8 illustrates a cross-sectional view of an entry guide useful in a medical robotic system utilizing aspects of the present invention.

FIG. 9 illustrates a perspective view of a proximal segment of an articulated instrument useful in a medical robotic system utilizing aspects of the present invention.

FIG. 10 illustrates a perspective view of a segment of an actuator assembly of an instrument manipulator that mates with and actuates an articulated instrument useful in a medical robotic system utilizing aspects of the present invention.

FIG. 11 illustrates a first perspective view of articulated instrument assemblies mounted on a platform coupled to a robotic arm assembly in a medical robotic system utilizing aspects of the present invention.

FIG. 12 illustrates a second perspective view of articulated instruments assemblies mounted on a platform coupled to a robotic arm assembly in a medical robotic system utilizing aspects of the present invention.

FIG. 13 illustrates a block diagram of components for controlling and selectively associating controllable devices with input devices of a medical robotic system utilizing aspects of the present invention.

FIG. 14 illustrates a side view of a pivoting entry guide with an articulated instrument extending out of its distal end in a medical robotic system utilizing aspects of the present invention.

FIG. 15 illustrates a side view of a pivoting entry guide with an articulated instrument retracted into the entry guide in a medical robotic system utilizing aspects of the present invention.

FIG. 16 illustrates a flow diagram of a method utilizing aspects of the present invention for re-orienting an entry guide with at least one articulated instrument disposed in it.

FIG. 17 illustrates a block diagram of components of a medical robotic system in an entry guide mode with coupled control of articulated instruments utilizing aspects of the present invention.

FIGS. 18A-18C illustrate top views of an entry guide in various stages of retracting articulated instruments into the entry guide in a medical robotic system utilizing aspects of the present invention.

FIG. 19 illustrates a flow diagram of a method utilizing aspects of the present invention for moving a plurality of articulated instruments in tandem back towards an entry guide.

FIG. 20 illustrates a force versus commanded position change relationship usable in a method utilizing aspects of the present invention for moving at least one articulated instrument back towards an entry guide.

FIG. 21 illustrates a velocity versus commanded position change relationship usable in a method utilizing aspects of the present invention for moving at least one articulated instrument back towards an entry guide.

FIG. 22 illustrates a block diagram of components of a medical robotic system in a camera mode with coupled control of articulated instruments utilizing aspects of the present invention.

FIG. 23 illustrates a block diagram of components of a medical robotic system in an instrument following mode with coupled control of articulated instruments utilizing aspects of the present invention.

FIG. 24 illustrates a flow diagram of an alternative method utilizing aspects of the present invention for moving a plurality of articulated instruments in tandem back towards an entry guide.

FIG. 25 illustrates a force versus commanded position change relationship usable in the alternative method utilizing aspects of the present invention for moving at least one articulated instrument back towards an entry guide.

FIG. 26 illustrates a velocity versus commanded position change relationship usable in the alternative method utilizing aspects of the present invention for retracting at least one articulated instrument back towards an entry guide.

FIG. 27 illustrates a flow diagram of a method utilizing aspects of the present invention for moving a plurality of articulated instruments in tandem back towards an entry guide after a delay.

FIG. 28 illustrates a first force contribution of the force versus commanded position change relationship of FIG. 25.

FIG. 29 illustrates a second force contribution of the force versus commanded position change relationship of FIG. 25.

FIG. 30 illustrates a force versus commanded position change relationship usable in a method utilizing aspects of the present invention for moving at least one articulated instrument back towards an entry guide after a delay with the instrument being pushed farther back during the delay.

FIG. 31 illustrates a velocity versus commanded position change relationship usable in a method utilizing aspects of the present invention for moving at least one articulated instrument back towards an entry guide after a delay with the instrument being pushed farther back during the delay.

FIG. 32 illustrates a force versus commanded position change relationship usable in a method utilizing aspects of the present invention for moving at least one articulated instrument back towards an entry guide after a delay with the instrument being allowed to recoil during the delay.

FIG. 33 illustrates a velocity versus commanded position change relationship usable in a method utilizing aspects of the present invention for moving at least one articulated instrument back towards an entry guide after a delay with the instrument being allowed to recoil during the delay.

FIG. 34 illustrates a flow diagram of a method utilizing aspects of the present invention for switching modes of a robotic system.

DETAILED DESCRIPTION

FIG. 1 illustrates, as an example, a schematic view of a medical robotic system 2100 in which instruments are inserted in a Patient through a single entry aperture through an entry guide. The system's general architecture is similar to the architecture of other such systems such as Intuitive Surgical, Inc.'s DA VINCI® Surgical System and the ZEUS® Surgical System. The three main components are a Surgeon console 2102, a Patient side support system 2104, and a video system 2106, all interconnected by wired or wireless connections 2108 as shown.

The Patient side support system 2104 includes a floor-mounted structure 2110, or alternately a ceiling mounted structure 2112 as shown by the alternate lines. It also includes a set-up arm assembly 2114, an entry guide manipulator (EGM) 2116, a platform 2118, an entry guide (EG) 2000, and one or more instrument assemblies 2500. The structure 2110 may be movable or fixed (e.g., to the floor, ceiling, or other equipment such as an operating table). In one embodiment, the set-up arm assembly 2114 includes two illustrative passive rotational setup joints 2114 a, 2114 b, which allow manual positioning of the coupled links when their brakes are released. A passive prismatic setup joint (not shown) between the arm assembly 2114 and the structure 2110 may be used to allow for large vertical adjustments.

The entry guide 2000 is coupled to the platform 2118, which in turn, is coupled to the entry guide manipulator 2116 so that the entry guide manipulator 2116 may pivot the platform 2118, which in turn, causes the entry guide 2000 to pivot about a Remote Center (RC) point. As shown in a perspective view of the entry guide 2000 in FIG. 4, the entry guide 2000 is generally cylindrical in shape and has a longitudinal axis X′ running centrally along its length. The RC point serves as an origin for both a fixed reference frame having X, Y and Z axes as shown and an entry guide reference frame having X′, Y′ and Z′ axes as shown. When the system 2100 is in an “entry guide” mode, the entry guide manipulator 2116 pivots the entry guide 2000, in response to movement of one or more associated input devices commanding such pivoting, about the Z axis (which remains fixed in space) at the RC point in yaw ψ. In addition, the entry guide manipulator 2116 pivots the entry guide 2000, in response to movement of the one or more input devices commanding such pivoting, about the Y′ axis (which is orthogonal to the longitudinal axis X′ of the entry guide 2000) in pitch θ; rotates the entry guide 2000, in response to movement of the one or more input devices commanding such rotation, about its longitudinal axis X′ in roll Φ; and optionally, linearly moving the entry guide 2000, in response to movement of the one or more input devices commanding such movement, along its longitudinal axis X′ in insertion/retraction or in/out “I/O” directions. Note that unlike the Z-axis which is fixed in space, the X′ and Y′ axes move with the entry guide 2000.

The entry guide manipulator 2116 includes illustrative active (i.e., actuatable) yaw joint 2116 a and active pitch joint 2116 b. Joints 2116 c and 2116 d act as a parallel mechanism so that the entry guide 2000 being held by the platform 2118 may pivot in yaw and pitch about the RC point which is positioned at an entry port 2120, such as an umbilicus of Patient 2122, prior to the performance of a medical procedure using the set-up arm assembly 2114. In one embodiment, an active prismatic joint 2124 may be used to insert and retract the entry guide 2000. One or more instrument assemblies 2500 such as assemblies for surgical instruments and an endoscopic imaging system are independently mounted to platform 2118 so as to be disposed within and extendable through the entry guide 2000.

Thus, the set-up arm assembly 2114 is used to position the entry guide 2000 in the entry port 2120 of the Patient 2122 when the Patient 2122 is placed in various positions on movable table 2126. After set-up of the entry guide 2000, instrument assemblies 2500 are mounted on the platform 2118 so that their articulated instruments extend into the entry guide 2000. The entry guide manipulator 2116 may then be used to pivot the entry guide 2000 and the articulated instruments disposed therein about the RC point in pitch and yaw. Rotation of the entry guide 2000 and/or insertion/retraction of the entry guide 2000 by the entry guide manipulator 2116 do not necessarily result in corresponding movement of the articulated instruments disposed therein, however.

As shown in FIG. 5, the entry guide manipulator (EGM) 2116 has four actuators 501-504 for actuating the four degrees-of-freedom movement of the entry guide 2000 (i.e., yaw ψ, pitch θ, roll Φ, and in/out I/O) and four corresponding assemblies 511-514 to implement them. The EGM yaw assembly 511 includes the yaw rotary joint 2116 a and one or more links that couple it through other parts of the entry guide manipulator 2116 to the platform 2118 so that when the EGM yaw actuator 501 (e.g., a motor) actuates (e.g., rotates) the yaw rotary joint, the entry guide 2000 is rotated about the fixed Z-axis at the RC point in yaw ψ. The EGM pitch assembly 512 includes the pitch rotary joint 2116 b and one or more links that couple it through other parts of the entry guide manipulator 2116 to the platform 2118 so that when the EGM pitch actuator 502 (e.g., a motor) actuates (e.g., rotates) the pitch rotary joint, the entry guide 2000 is rotated about the Y′-axis at the RC point in pitch θ. The EGM roll assembly 513 includes a gear assembly that couples the entry guide 2000 to an EGM roll actuator 503 so that when the EGM roll actuator 503 (e.g., a motor) actuates (e.g., its rotor rotates), the entry guide 2000 rotates about its longitudinal axis X′ in response. In one embodiment, the EGM I/O assembly 514 includes a prismatic joint that is coupled to the EGM I/O actuator 504 so that when the EGM I/O actuator 504 (e.g., a motor) actuates (e.g., its rotor rotates), the rotary action is transferred into a linear displacement of the entry guide 2000 along its longitudinal axis X′. In another embodiment, rather than moving the entry guide 2000 in the insertion/retraction direction, all articulated instruments disposed in the entry guide 2000 are moved instead in the insertion/retraction direction in response to an EG I/O command.

FIGS. 2 and 3 illustrate, as examples, alternative embodiments of the Patient side support system 2104. Support 2150 is fixed (e.g., floor or ceiling mounted). Link 2152 is coupled to support 2150 at passive rotational setup joint 2154. As shown, joint 2154's rotational axis is aligned with RC point 2156, which is generally the position at which an entry guide (not shown) enters the Patient (e.g., at the umbilicus for abdominal surgery). Link 2158 is coupled to link 2152 at rotational joint 2160. Link 2162 is coupled to link 2158 at rotational joint 2164. Link 2166 is coupled to link 2162 at rotational joint 2168. The entry guide is mounted to slide through the end 2166 a of link 2166. Platform 2170 is supported and coupled to link 2166 by a prismatic joint 2172 and a rotational joint 2174. Prismatic joint 2172 inserts and retracts the entry guide as it slides along link 2166. Joint 2174 includes a bearing assembly that holds a “C” shaped ring cantilever. As the “C” ring slides through the bearing it rotates around a center point inside the “C”, thereby rolling the entry guide. The opening in the “C” allows entry guides to be mounted or exchanged without moving overlying manipulators. Platform 2170 supports multiple instrument manipulators 2176 for surgical instruments and an imaging system, as described below.

These illustrative robotic arm assemblies (i.e., set-up arm assemblies and entry guide manipulators) are used, for example, for instrument assemblies that include a rigid entry guide and are operated to move with reference to a Remote Center (RC) point. Certain setup and active joints in the robotic arm assemblies may be omitted if motion around a remote center is not required. It should be understood that set-up and manipulator arms may include various combinations of links, passive, and active joints (redundant DOFs may be provided) to achieve a necessary range of poses for surgery.

Referring again to FIG. 1, the video system 2106 performs image processing functions for, e.g., captured endoscopic imaging data of the surgical site and/or preoperative or real time image data from other imaging systems external to the Patient. Video system 2106 outputs processed image data (e.g., images of the surgical site, as well as relevant control and Patient information) to the Surgeon at the Surgeon console 2102. In some aspects the processed image data is output to an optional external monitor visible to other operating room personnel or to one or more locations remote from the operating room (e.g., a Surgeon at another location may monitor the video; live feed video may be used for training; etc.).

FIG. 6 illustrates, as an example, a front view of the Surgeon console 2102 which a Surgeon or other user operates for controlling movement of the entry guide and articulated instruments of the system 2100. The Surgeon console 2102 has left and right input devices 41, 42 which the user may grasp respectively with his/her left and right hands to manipulate associated devices, such as the entry guide and articulated instruments, in preferably six degrees-of-freedom. Foot pedals 44 with toe and heel controls are provided on the Surgeon console 2102 so the user may control movement and/or actuation of devices associated with the foot pedals. A processor 43 is provided in the Surgeon console 2102 for control and other purposes. Although shown as a single processor located in the base of the Surgeon console 2102, the processor 43 may be implemented as multiple cooperative processors distributed in the Surgeon console 2102 as well as other parts of the medical robotic system 2100. A stereo viewer 45 is also provided in the Surgeon console 2102 so that the user may view the work site in stereo vision from images captured by a stereoscopic camera of an articulated camera instrument. Left and right eyepieces, 46 and 47, are provided in the stereo viewer 45 so that the user may view left and right 2-D display screens inside the viewer 45 respectively with the user's left and right eyes.

The Surgeon console 2102 is usually located in the same room as the Patient 2122 so that the Surgeon may directly monitor the procedure, is physically available if necessary, and is able to speak to any assistants in the operating room directly rather than over the telephone or other communication medium. However, it will be understood that the Surgeon can also be located in a different room, a completely different building, or other remote location from the Patient allowing for remote surgical procedures.

As shown in FIG. 7, the entry guide 2000 has articulated instruments such as articulated surgical tool instruments 231, 241 and an articulated stereo camera instrument 211 (or other image capturing device instrument) extending out of its distal end. The camera instrument 211 has a pair of stereo image capturing devices 311, 312 and a fiber optic cable 313 (coupled at its proximal end to a light source) housed in its tip. The surgical tools 231, 241 have end effectors 331, 341. Although only two tools 231, 241 are shown, the entry guide 2000 may guide additional tools as required for performing a medical procedure at a work site in the Patient. For example, as shown in FIG. 8, a passage 351 is available for extending another articulated surgical tool through the entry guide 2000 and out through its distal end. Passages 431, 441, and 321 are respectively used by the articulated surgical tool instruments 231, 241, and articulated camera instrument 211. Each of the surgical tools 231, 241 is associated with one of the input devices 41, 42 in a tool following mode. The Surgeon performs a medical procedure by manipulating the input devices 41, 42 so that the controller 43 causes corresponding movement of their respectively associated surgical tools 231, 241 while the Surgeon views the work site in 3-D on the console stereo viewer 45 as images of the work site are being captured by the articulated camera instrument 211.

Preferably, input devices 41, 42 will be provided with at least the same degrees of freedom as their associated tools 231, 241 to provide the Surgeon with telepresence, or the perception that the input devices 41, 42 are integral with the tools 231, 241 so that the Surgeon has a strong sense of directly controlling the tools 231, 241. To this end, the stereo viewer 45 is also positioned near the Surgeon's hands as shown so that it will display a projected image that is oriented so that the Surgeon feels that he or she is actually looking directly down onto the work site and images of the tools 231, 241 appear to be located substantially where the Surgeon's hands are located.

In addition, the real-time image on the stereo viewer 45 is preferably projected into a perspective image such that the Surgeon can manipulate the end effectors 331, 341 of the tools 231, 241 through their corresponding input devices 41, 42 as if viewing the work site in substantially true presence. By true presence, it is meant that the presentation of an image is a true perspective image simulating the viewpoint of an operator that is physically manipulating the end effectors 331, 341. Thus, the processor 43 transforms the coordinates of the end effectors 331, 341 to a perceived position so that the perspective image being shown on the stereo viewer 45 is the image that the Surgeon would see if the Surgeon was located directly behind the end effectors 331, 341.

The processor 43 performs various functions in the system 2100. One important function that it performs is to translate and transfer the mechanical motion of input devices 41, 42 through control signals over communication means 2108 to actuate actuators in their associated manipulators so that the Surgeon can effectively manipulate devices, such as the tool instruments 231, 241, camera instrument 211, and entry guide 2000. Another function is to perform various methods and implement various controllers and coupling logic described herein.

Although described as a processor, it is to be appreciated that the processor 43 may be implemented by any combination of hardware, software and firmware. Also, its functions as described herein may be performed by one unit or divided up among different components, each of which may be implemented in turn by any combination of hardware, software and firmware. Further, although being shown as part of or being physically adjacent to the console 2102, the processor 43 may also comprise a number of subunits distributed throughout the system.

For additional details on the construction and operation of various aspects of a medical robotic system such as described herein, see, e.g., U.S. Pat. No. 6,493,608 “Aspects of a Control System of a Minimally Invasive Surgical Apparatus”; U.S. Pat. No. 6,671,581 “Camera Referenced Control in a Minimally Invasive Surgical Apparatus”; and U.S. 2008/0071288 A1 “Minimally Invasive Surgery Guide Tube”; each of which is incorporated herein by reference.

Mounting of the instrument assemblies 2500 onto the platform 2118 with their working ends inserted into the entry guide 2000 is now described in reference to FIGS. 9-12. As shown in FIG. 9, articulated instrument 2402 includes a transmission mechanism 2404 coupled to the proximal end of an instrument body tube 2406. Components at body tube 2406's distal end 2408 are omitted for clarity and may include actuatable joints and working ends as shown in FIG. 7. In the illustrative embodiment shown, transmission mechanism 2404 includes six interface disks 2410. Each of the disks 2410 may be associated with a Degree-of-Freedom (DOF) for the articulated instrument 2402. For instance, one disk may be associated with instrument body roll DOF, and a second disk may be associated with end effector grip DOF. As shown, in one instance the disks are arranged in a hexagonal lattice for compactness—in this case six disks in a triangular shape. Other lattice patterns or more arbitrary arrangements may be used. Mechanical components (e.g., gears, levers, gimbals, cables, etc.) inside transmission mechanism 2404 transmit roll torques on disks 2410 to e.g., body tube 2406 (for roll) and to components coupled to distal end mechanisms. Cables and/or cable and hypotube combinations that control distal end DOFs run through body tube 2406. In one instance the body tube is approximately 7 mm in diameter, and in another instance it is approximately 5 mm in diameter. Raised pins 2412, spaced eccentrically, provide proper disk 2410 orientation when mated with an associated actuator disk. One or more electronic interface connectors 2414 provide an electronic interface between instrument 2402 and its associated actuator mechanism. The electronic interface may also include power for, e.g., an electrocautery end effector. Alternately, such a power connection may be positioned elsewhere on instrument 2402 (e.g., on transmission mechanism 2404's housing). Other connectors for, e.g., optical fiber lasers, optical fiber distal bend or force sensors, irrigation, suction, etc. may be included. As shown, transmission mechanism 2404's housing is roughly wedge or pie-shaped to allow it to be closely positioned to similar housings, as illustrated below.

FIG. 10 is a perspective view of a portion of an actuator assembly 2420 (also referred to herein as an instrument “manipulator”) that mates with and actuates components in surgical instrument 2402. Actuator disks 2422 are arranged to mate with interface disks 2410. Holes 2424 in disks 2422 are aligned to receive pins 2412 in only a single 360-degree orientation. Each disk 2422 is turned by an associated rotating servomotor actuator 2426, which receives servocontrol inputs from its respective controller as described below. A roughly wedge-shaped mounting bracket 2428, shaped to correspond to instrument 2402's transmission mechanism housing, supports the disks 2422, servomotor actuators 2426, and an electronic interface 2430 that mates with instrument 2402's interface connectors 2414. In one instance instrument 2402 is held against actuator assembly 2420 by spring clips (not shown) to allow easy removal. As shown in FIG. 10, a portion 2432 of actuator assembly housing 2428 is truncated to allow instrument body tube 2406 to pass by. Alternatively, a hole may be placed in the actuator assembly to allow the body tube to pass through.

FIG. 11 is a diagrammatic perspective view that illustrates aspects of mounting minimally invasive surgical instruments and their associated actuator assemblies at the end of a setup/manipulator arm. As shown in FIG. 11, surgical instrument 2502 a is mounted on actuator assembly 2504, so that the transmission mechanism mates with the actuator assembly as described above. Instrument 2502 a's body tube 2506 extends past actuator assembly 2504 and enters a port in rigid entry guide 2508. As depicted, body tube 2506, although substantially rigid, is bent slightly between the transmission mechanism housing and the entry guide. This bending allows the instrument body tube bores in the entry guide to be spaced closer than the size of their transmission mechanisms would otherwise allow. Since the bend angle in the rigid instrument body tube is less than the bend angle for a flexible (e.g., flaccid) instrument body, cables can be stiffer than in a flexible body. High cable stiffness is important because of the number of distal DOFs being controlled in the instrument. Also, the rigid instrument body is easier to insert into an entry guide than a flexible body. In one embodiment the bending is resilient so that the body tube assumes its straight shape when the instrument is withdrawn from the entry guide (the body tube may be formed with a permanent bend, which would prevent instrument body roll). Actuator assembly 2504 is mounted to a linear actuator 2510 (e.g. a servocontrolled lead screw and nut or a ball screw and nut assembly) that controls body tube 2506's insertion within entry guide 2508. The second instrument 2502 b is mounted with similar mechanisms as shown. In addition, an imaging system (not shown) may be similarly mounted.

FIG. 11 further shows that entry guide 2508 is removably mounted to support platform 2512. This mounting may be, for example, similar to the mounting used to hold a cannula on a DA VINCI® Surgical System manipulator arm. Removable and replaceable entry guides allow different entry guides that are designed for use with different procedures to be used with the same telemanipulative system (e.g., entry guides with different cross-sectional shapes or various numbers and shapes of working and auxiliary channels). In turn, actuator platform 2512 is mounted to robot manipulator arm 2514 (e.g., 4 DOF) using one or more additional actuator mechanisms (e.g., for pitch, yaw, roll, insertion). In turn, manipulator arm 2514 may be mounted to a passive setup arm, as described above with reference to the entry guide manipulator 2116 of FIG. 1.

FIG. 12 is a diagrammatic perspective view that illustrates aspects shown in FIG. 11 from a different angle and with reference to a Patient. In FIG. 12, arm 2514 and platform 2512 are positioned so that entry guide 2508 enters the Patient's abdomen at the umbilicus. This entry is illustrative of various natural orifice and incision entries, including percutaneous and transluminal (e.g., transgastric, transcolonic, transrectal, transvaginal, transrectouterine (Douglas pouch), etc.) incisions. FIG. 12 also illustrates how the linear actuators for each instrument/imaging system operate independently by showing imaging system 2518 inserted and instruments 2502 a, 2502 b withdrawn. It can be seen that in some instances the manipulator arm 2514 moves to rotate or pivot entry guide 2508 around a Remote Center (RC) 2520 at the entry port into a Patient. If intermediate tissue restricts movement around a remote center, however, the arm can maintain entry guide 2508 in position.

FIG. 13 illustrates, as an example, a block diagram of components used for controlling and selectively associating articulated instruments on the Patient side support system 2104 to operator manipulated input devices 41, 42 of the Surgeon console 2102. Various surgical tools such as graspers, cutters, and needles may be used to perform a medical procedure at a work site within the Patient. In this example, three articulated surgical tool instruments (TOOL1, TOOL2, TOOL3) 2231, 2241, 2251 are used to robotically perform the procedure and an articulated imaging system instrument (IS) 2261 is used to view the procedure. In other examples, more or less instruments may be used. The imaging system 2261 may be a stereoscopic camera instrument, such as camera instrument 211, or another type of imaging system such as a monoscopic camera instrument or an ultrasound probe instrument. The tools 2231, 2241, 2251 and imaging system 2261 may be disposed in an entry guide (EG) 2000 so as to be extendable beyond a distal end of the entry guide 2000. The entry guide 2000 may be inserted into the Patient through an entry aperture such as a minimally invasive incision or a natural orifice using the setup portion of a robotic arm assembly and maneuvered by an entry guide manipulator (EGM) 2116 towards the work site where the medical procedure is to be performed.

Each of the devices 2231, 2241, 2251, 2261, 2000 is manipulated by its own manipulator. In particular, the imaging system (IS) 2261 is manipulated by an imaging system manipulator (PSM4) 2262, the first surgical tool (TOOL1) 2231 is manipulated by a first tool manipulator (PSM1) 2232, the second surgical tool (TOOL2) 2241 is manipulated by a second tool manipulator (PSM2) 2242, the third surgical tool (TOOL3) 2251 is manipulated by a third tool manipulator (PSM3) 2252, and the entry guide (EG) 2000 is manipulated by the entry guide manipulator (EGM) 2116.

Each of the instrument manipulators 2232, 2242, 2252, 2262 is a mechanical assembly that carries actuators and provides a mechanical, sterile interface to transmit motion to its respective articulated instrument. Each of the articulated instruments 2231, 2241, 2251, 2261 is a mechanical assembly that receives the motion from its manipulator and, by means of a cable transmission, propagates the motion to its distal articulations (e.g., joints). Such joints may be prismatic (e.g., linear motion) or rotational (e.g., they pivot about a mechanical axis). Furthermore, the instrument may have internal mechanical constraints (e.g., cables, gearing, cams, belts, etc.) that force multiple joints to move together in a pre-determined fashion. Each set of mechanically constrained joints implements a specific axis of motion, and constraints may be devised to pair rotational joints (e.g., joggle joints). Note also that in this way the instrument may have more joints than the available actuators.

In direct control mode, each of the input devices 41, 42 may be selectively associated with one of the devices 2261, 2231, 2241, 2251, 2000 through a multiplexer (MUX) 2290 so that the associated device may be controlled by the input device through its controller and manipulator. For example, the Surgeon may specify the association through a graphical user interface (GUI) 2291 on the Surgeon console 2102 for the left and right input devices 41, 42 to be respectively associated with the first and second surgical tools 2231, 2241, which are telerobotically controlled through their respective controllers 2233, 2243 and manipulators 2232,2242 so that the Surgeon may perform a medical procedure on the Patient while the surgical tool 2251, imaging system 2261 and entry guide 2000 are each soft locked in place through their respective controllers. If the Surgeon desires to control movement of the surgical tool 2251 using one of the input devices 41, 42, then the Surgeon may do so by simply disassociating the input device from its currently associated device and associating it instead to the tool 2251. Likewise, if the Surgeon desires to control movement of either the imaging system 2261 or entry guide 2000 using one or both of the input devices 41, 42, then the Surgeon may do so by simply disassociating the input device from its currently associated device and associating it instead to the imaging system 2261 or entry guide 2000.

As alternatives to using the GUI 2291 for providing selection input SEL for the MUX 2290, the selective association of the input devices 41, 42 to devices 2251, 2241, 2231, 2261, 2000 may be performed by the Surgeon using voice commands understood by a voice recognition system, or by the Surgeon depressing a button on one of the input devices 41, 42, or by the Surgeon depressing a foot pedal on the Surgeon console 2102, or by the Surgeon using any other well known mode switching technique. Although such mode switching is described herein as being performed by the Surgeon, it may alternatively be performed by an Assistant under the direction of the Surgeon.

Each of the controllers 2233, 2243, 2253, 2263, 2273 comprises a master/slave control system that includes a joint controller for each joint of its respective articulated instrument or in the case of the entry guide 2000, its manipulator 2116. To simplify the description herein and in the claims, the term “joint” is to be understood as a connection (translational or revolute) between two links, and may include gears (or prismatic joints) as well as any other controllable component coupled to linear drive mechanisms that may be used in controlling robotic arm assemblies. An example of such a control system is described in previously incorporated by reference and U.S. Pat. No. 6,424,885, “Camera Referenced Control in a Minimally Invasive Surgical Apparatus.”

Direct control modes are control modes in which the user has direct control over a specific slave manipulator. All other slave manipulators (i.e., the ones that are not connected to an input device) may be soft-locked (i.e., all their joints are held in place by their respective controllers). As an example, in a single-port system such as described herein, three direct control modes are defined as a direct “tool following” mode in which the two hand-operable input devices are associated with two tool slave manipulators and their respective tools, a direct “imaging system” mode in which one or both of the hand-operable input devices are associated with the imaging system, and a direct “entry guide” mode in which one or both hand-operable input devices are associated with the entry guide.

In a coupled control mode, the Surgeon is directly controlling movement of an associated slave manipulator (e.g., one of the manipulators 2232, 2242, 2252, 2262, 2116) while indirectly controlling movement of one or more non-associated slave manipulators, in response to commanded motion of the directly controlled slave manipulator, to achieve a secondary objective. By automatically performing secondary tasks through coupled control modes, the system's usability is enhanced by reducing the Surgeon's need to switch to another direct mode to manually achieve the desired secondary objective. Thus, coupled control modes allow the Surgeon to better focus on performing the medical procedure and to pay less attention to managing the system.

The GUI 2291 used by the Surgeon to specify the association of inputs devices 41, 42 and devices 2231,2241,2251,2261,2000 may also be used by the Surgeon to specify various parameters of the coupled control modes. For example, the Surgeon may use the GUI 2291 to select which device manipulators participate in various coupled control modes and to define and/or prioritize the secondary objectives associated with the coupled control modes.

In “entry guide” mode, both input devices 41, 42 may be used to move the entry guide 2000 as the Surgeon views on the stereo viewer 45 processed images that were originally captured by the camera 211. An image referenced control is implemented in the entry guide controller 2273 so that the controller 2273 controls movement of the entry guide 2000 while the Surgeon is given the impression that he or she is moving the image captured by the camera 211. In particular, the Surgeon is provided with the sensation that he or she is grasping the image being displayed on the viewer 45 with his or her left and right hands and moving the image about the work site to a desired viewing point. Note that under this control, the image on the viewer 45 appears to move in opposite directions in response to movement of the input devices 41, 42. For example, the image moves to the right when the input devices 41, 42 move to the left (and vice versa). Also, the image moves up when the input devices 41, 42 are moved down (and vice versa). Pivoting of the entry guide is accomplished using a “virtual handlebar” in which pivot points of the left and right input devices 41, 42 define a handle bar axis which passes through the pivot points. An entry guide yaw command may then be generated by the Surgeon moving one input device forward while moving the other one back. An entry guide pitch command, on the other hand, may be generated by the Surgeon pivoting both input devices about the handle bar axis in the same direction (either up to pitch up or down to pitch down). An entry guide roll command may be generated by the Surgeon moving one input device up while moving the other input device down. An insertion command may be generated by the Surgeon moving both input devices backward and a retraction command may be generated by the Surgeon moving both input device forward.

When the Surgeon is operating in the “entry guide” mode to re-orient the entry guide 2000 along with all of the articulated instruments within it at the time, the Surgeon may inadvertently strike and harm the patient's anatomy with an articulated instrument that is extending out of the distal end of entry guide when the entry guide is being pivoted about its Remote Center (RC). For example, referring to FIG. 14, an articulated instrument 1400 is shown in solid line form extending out of the distal end of the entry guide 2000 at an initial orientation and shown in dotted line form striking the patient anatomy 1410 after being pivoted about the RC point. Although a distal end of the articulated instrument is shown as striking the patient anatomy in this example, in practice, it is to be appreciated that other parts of an articulated instrument such as more proximal (i.e., closer to the entry guide) links of the articulated instruments 211, 231, 241 may also potentially strike patient anatomy due to the articulated nature of the instruments. In addition, it may be difficult for a Surgeon to foresee such striking when viewing the work site on the stereo viewer 45 since the proximal links may be out of the field of view of the camera instrument 211. Thus, to avoid inadvertently striking and harming the patient anatomy, it is advisable to retract all articulated instruments back into the entry guide before re-orienting the entry guide, such as shown, for example, in FIG. 15, when large adjustments to the orientation of the entry guide 2000 are being made.

When there is a plurality of articulated instruments extending out of the entry guide 2000, such as shown in FIG. 7, it may be tedious and time consuming for the Surgeon to change modes between “entry guide” and “tool following” modes, place the articulated instruments one-at-a-time into a retraction configuration (i.e., one in which the instrument may be retracted into the entry guide) while changing associations between the input devices and instruments as necessary, and retracting each of the articulated instruments after its reconfiguration into the entry guide 2000. Therefore, it would be useful to provide a coupled control structure in which the entry guide controller 2273 is coupled to instrument controllers 2233, 2243, 2253, 2263 during “entry guide” mode so that the controllers 2233, 2243, 2253, 2263 automatically reconfigure and retract their respective articulated instruments upon receiving an indication to do so from the entry guide controller 2273. Reconfiguration and retraction of the articulated instruments may be performed sequentially (or concurrently when safe to do so) in this case either under the control of the Surgeon or automatically by the system while avoiding collisions among the instruments and with their environment.

An example of such a coupled control structure is now described, wherein FIG. 16 illustrates a flow diagram including a method for re-orienting an entry guide having a plurality of extendable articulated instruments disposed within it and FIG. 17 illustrates a coupled control structure which includes one or more coupling logic blocks for implementing aspects of the method of FIG. 16.

Referring to FIG. 16, in block 1601, the method receives an indication that the “entry guide” mode has been entered, as described, for example, in reference to FIG. 13. In block 1602, the method, in response to operator commands to do so, concurrently retracts all articulated instruments extending out of the distal end of the entry guide back into the entry guide either completely or at least to a point where they cannot harm the patient anatomy while the entry guide is being pivoted about the Remote Center (RC) pivot point. FIGS. 18A-18C serve to illustrate general aspects of the retraction performed in block 1602.

In FIG. 18A, a top view of the entry guide 2000 is shown with articulated instruments 231, 241, 211 extending out of its distal end such as shown in the perspective view of FIG. 7. In FIG. 18B, the articulated instruments 231, 241, 211 are shown in their retraction configurations wherein their links line up so as to be retractable into a corresponding lumen or space in the entry guide 2000. In FIG. 18C, the articulated tool instruments 231, 241 are shown fully retracted into the entry guide 2000 while the articulated camera instrument 211 is shown only partially retracted (or alternatively retracted so as to be just inside the entry guide) so that it may still capture a view out of the distal end while not risking harm to the patient anatomy when the entry guide 2000 is being pivoted about the RC pivot point. Alternatively, the articulated instruments 231, 241, 211 may not be fully retracted into the entry guide 2000, but only enough so that none of them may harm (or be placed in a position so as to cause unintended harm to) any patient anatomy when the entry guide 2000 is subsequently pivoted about the Remote Center (RC) to re-orient the entry guide 2000. Note that in this case, the articulated instruments 231, 241, 211 may be allowed to touch patient anatomy as long as the touching does not result in harming the patient anatomy.

Although the sequence shown in FIGS. 18A-18C suggests that the reconfiguration occurs before retraction starts, in practicing the invention, the sequence of retraction and reconfiguration of the plurality of articulated instruments may be performed concurrently or in a different order depending upon certain conditions and the method employed.

As first method of the retraction and reconfiguration sequence, if the most proximal joint of the plurality of articulated instruments (e.g. joint 323 of the articulated camera instrument 211 in FIG. 18A) is at a minimum distance away from the distal end of the entry guide 2000, then retraction may be allowed to occur concurrently with reconfiguration with a straightening velocity that is proportional to the retraction velocity (subject to maximum velocity limits). During reconfiguration and retraction, collisions between the reconfiguring and/or retracting instruments should be predicted by the system and avoided, as well as avoiding harm to the patient anatomy. The velocity with which the articulated instruments may be retracted and/or reconfigured is preferably a function of how hard the Surgeon is pushing against any haptic feedback being provided on the controlling input device during the retraction and/or reconfiguration. If the most proximal joint (that is not in the entry guide 2000 at the time) of the plurality of articulated instruments reaches the distal end of the entry guide 2000 before its articulated instrument has been fully reconfigured to its retraction configuration, then further retraction of the plurality of articulated instruments is prevented by the system until reconfiguration of the most proximal joint's articulated instrument into its retraction configuration has completed. This requirement is to avoid damage to the articulated instrument and/or entry guide 2000. In this case, the velocity for reconfiguration may still be a function of how hard the Surgeon is pushing against any haptic force being provided on the controlling input device, but possibly with a different gain. The minimum distance from the distal end of the entry guide 2000 at which concurrent retraction and reconfiguration may occur may be determined by consideration of several factors. One factor is the velocity at which in tandem movement of the articulated instruments is being commanded (e.g., the faster the commanded retraction movement, the larger the minimum distance; and the faster the reconfiguration movement, the smaller the minimum distance). Another factor is the initial configurations of the articulated instruments. For example, the closer the initial configurations of the plurality of articulated instruments are to their retraction configurations, the shorter the minimum distance, and vice versa. Also, since it is undesirable for the distal ends of the articulated instruments to extend forward beyond their initial positions during reconfiguration, because doing so may inadvertently harm the patient anatomy, compensation for such extension is required in the retraction direction. Therefore, the amount of such extension compensation is still another factor in determining the minimum distance.

As another and simpler method of the retraction and reconfiguration sequence, retraction may occur before reconfiguration. For example, the plurality of articulated instruments may be retracted in tandem until a most proximal joint (not already in the entry guide) of one of the articulated instruments reaches the distal end of the entry guide 2000, whereupon further retraction is prohibited by the system and reconfiguration of the articulated instrument into its retraction configuration is initiated. Once reconfiguration for that articulation instrument has completed, then the plurality of articulated instruments may be retracted in tandem again until a most proximal joint (not already in the entry guide) of one of the articulated instruments reaches the distal end of the entry guide 2000, whereupon further retraction is once again prohibited by the system and reconfiguration of that articulated instrument into its retraction configuration is initiated if necessary. The above described sequence would then continue until all of the plurality of articulated instruments has been thus reconfigured and retracted into the entry guide 2000.

Referring back to FIG. 16, in block 1603, the method, in response to operator commands to do so, pivots the entry guide 2000 about the RC pivot point to a new orientation. After completing the re-orientation of the entry guide 2000, in block 1604, the articulated instruments 231, 241, 211 may then be re-inserted in response to operator commands to do so, and in block 1605, the operator may exit the “entry guide” mode and enter “tool following” mode so that the operator (e.g., Surgeon) may perform or continue to perform a medical procedure on the patient with the re-positioned entry guide 2000 and articulated instruments 231, 241, 211.

FIG. 19 illustrates, as an example, a flow diagram of a method for moving a plurality of articulated instruments in tandem back towards an entry guide, which method may be implemented by the coupled control structure of FIG. 17 and used to perform the articulated instrument retractions in block 1602 of FIG. 16.

In block 1901, the method receives information of a commanded change in the position (q_(IO)) of the entry guide 2000 in a direction parallel to the entry guide's insertion axis X′. The commanded position change in this case is relative to the RC point, which serves as an initial position from which the change in position is determined. In one embodiment, the commanded position change (q_(IO)) may be made by the Surgeon commanding the entry guide 2000 to move along its insertion axis X′ when the system is in “entry guide” mode. In this case, however, instead of moving the entry guide 2000 along its insertion axis X′, all articulated instruments extending out of the distal end of the entry guide 2000 are to be retracted back according to the commanded position change (q_(IO)).

In block 1902, the method makes a determination whether the commanded position change (q_(IO)) is greater than a limit distance (IO_(LIM)). If the determination is NO, then the method loops back to block 1901 to receive information of another commanded position change (q_(IO)). On the other hand, if the determination in block 1902 is YES, then in block 1903, the method causes a haptic force to be applied against a control mechanism, which the operator uses to generate the commanded position change (q_(IO)), in a manner so as to progressively increase in force as the position change commands along the insertion axis X′ generated by the operator manipulating the control mechanism progressively exceed the limit distance (IO_(LIM)), as depicted, for example, in the force versus commanded position change function f(q_(IO)) of FIG. 20. The control mechanism in this case may include one or both of the input devices 41, 42 of the Surgeon console 2102.

In block 1904, the method makes a determination whether the commanded position change (q_(IO)) is greater than a locking distance (IO_(LOCK)), wherein the locking distance is greater than the limit distance. If the determination is NO, then the method loops back to block 1901 to receive information of another commanded position change (q_(IO)). On the other hand, if the determination in block 1904 is YES, then in block 1905, the method causes pivot joints of the entry guide manipulator (EGM) 2116 to be soft-locked in place using their respective joint controllers.

In block 1906, the method makes a determination whether the commanded position change (q_(IO)) is greater than a retraction-on distance (IO_(ON)), wherein the retraction-on distance is greater than the locking distance. If the determination is NO, then the method loops back to block 1901 to receive information of another commanded position change (q_(IO)). On the other hand, if the determination in block 1906 is YES, then in block 1907, the method causes the arms (e.g., the combination of joints and links) of the articulated instruments to be straightened so as to be in proper retraction configurations while concurrently in block 1908, the retractions of the articulated instruments are subjected to a progressively increasing velocity limit by the method as the commanded position change (q_(IO)) progressively exceeds the retraction-on distance, as depicted, for example, in the velocity versus commanded position change function g(q_(IO)) of FIG. 21.

In block 1909, the method makes a determination whether the commanded position change (q_(IO)) is greater than a maximum distance (IO_(MAX)), wherein the maximum distance is greater than the retraction-on distance. If the determination is NO, then the method loops back to block 1901 to receive information of another commanded position change (q_(IO)). On the other hand, if the determination in block 1909 is YES, then in block 1910, the retractions of the articulated instruments are subject to a maximum velocity limit (V_(MAX)) as the commanded position changes progressively exceed the maximum distance, as depicted, for example, in the velocity versus commanded position change (q_(IO)) function of FIG. 21.

In block 1911, the method determines whether all articulated instruments previously extending out of the distal end of the entry guide 2000 are now in their retracted positions in the entry guide 2000. A retracted position in this case does not necessarily mean that the instrument is completely retracted into the entry guide 2000. As shown in FIG. 18C, for example, the articulated camera instrument 211 may still have its image capturing end exposed out of the entry guide 2000 so that it may get a better view of the surrounding area when the entry guide 2000 is being re-oriented by pivoting it about the RC point. This allows the Surgeon to view the portion of the patient anatomy where the entry guide 2000 is being re-oriented towards. Other articulated instruments may also be only partially retracted as long as their extended portions do not strike and harm the patient anatomy during the entry guide 2000 pivoting.

If the determination in block 1911 is NO, then the method loops back to block 1901 to receive information of another commanded position change (q_(IO)). On the other hand, if the determination in block 1911 is YES, then in block 1912, the method causes pivot joints of the entry guide manipulator (EGM) 2116 to no longer be soft-locked in place by their respective joint controllers. At this point, the entry guide 2000 may be re-oriented along with all articulated instruments disposed within it and the instruments may then be extended out of the entry guide 2000 so as to be positioned to perform or continue to perform a medical procedure on the patient.

Referring to FIG. 17, the methods described in reference to FIGS. 16 and 19 may be implemented in one or more of an EG coupling logic 1700, PSM1 coupling logic 1701, PSM2 coupling logic 1702, and PSM4 coupling logic 1704 for the example in which articulated instruments 2231, 2241, 2261 are disposed within the entry guide 2000. If more or less articulated instruments are extendable through the entry guide 2000, then the coupling structure of FIG. 17 may be modified accordingly. Although shown as separate components, the coupling logic 1700, 1701, 1702, 1704 may be structured as a single logic block by, for example, incorporating all logic into the EG coupling logic 1700, or it may be structured in a distributed processing fashion by, for example, eliminating the EG coupling logic 1700 and distributing the processing among the PSM1, PSM2, and PSM4 coupling logic 1701, 1702, 1704. Also, although shown as being separate from their respective controllers, each of the coupling logic blocks may be integrated into their respective controllers such as the EG coupling logic 1700 being integrated as part of the entry guide controller (CNTLG) 2273. Further, the processor 43 may implement all control and coupling logic shown in FIG. 17 using computer program code stored in a memory unit of the system 2100. To simplify the drawing, block 2274 represents the combination of the entry guide manipulator 2116 and entry guide 2000. Block 2264 represents the combination of the imaging system instrument manipulator 2262 and imaging system instrument 2261. Block 2234 represents the combination of the tool instrument manipulator 2232 and tool instrument 2231. Block 2244 represents the combination of the instrument manipulator 2242 and tool instrument 2241.

Although the moving of the articulated instruments 211, 231, 241 in tandem back towards the entry guide 2000 is described above in reference to re-orienting the entry guide 2000, it may also be useful to move a plurality of articulated instruments in tandem back towards the entry guide in other applications such as, for example, after the completion of a medical procedure. In these cases, rather than switching to the “entry guide” mode, the system may stay in an “imaging system” mode and make use of coupled control logic such as illustrated in FIG. 22 to move the articulated instruments 211, 231, 241 in tandem back towards the entry guide 2000. Likewise, the system may stay in a “tool following” mode and make use of coupled control logic such as illustrated in FIG. 23 to move the articulated instruments 211, 231, 241 in tandem back towards the entry guide 2000. In either case, the movement of the articulated instruments in tandem back towards the entry guide 2000 is performed in a similar manner as previously described with respect to FIGS. 19-21 with the exception that the pivot joints of the entry guide 2000 do not need to be locked. This is because under both “imaging system” mode and “tool following” mode, the entry guide 2000 is already locked in place (as illustrated, for example, in FIGS. 22, 23 by the “soft-locking” feedback from the entry guide and entry guide manipulator combination block 2274 to the entry guide controller 2273). Thus, FIGS. 24-26 illustrate a method for moving a plurality of articulated instruments (e.g., 211, 231, 241) in tandem back towards the entry guide 2000 that may be performed during “imaging system” and “tool following” modes, wherein FIG. 24 is performed substantially the same manner as described in reference to FIG. 19 with the exception that blocks 1904, 1905, 1912 related to locking the entry guide in place are deleted and FIGS. 25, 26 are respectively essentially the same as FIGS. 20, 21 with the exception that the point IO_(LOCK) related to locking the entry guide in place has been deleted.

FIG. 27 illustrates, as an example, a flow diagram of a method for moving a plurality of articulated instruments in tandem back towards an entry guide after a delay. The method of FIG. 27 is a modified version of the method described in reference to FIG. 19. To simplify its description, blocks that are performed in the same manner in FIGS. 19 and 27 have the same reference numbers. The method of FIG. 27 may be implemented by the coupled control structure of FIG. 17 and used to perform the articulated instrument retractions in block 1602 of FIG. 16.

In the method of FIG. 27, the force versus commanded position change function, f(q_(IO)), which was previously described in reference to block 1904 of FIG. 19, is split into two parts. A first part, f₁(q_(IO)), as indicated in FIG. 28 by reference number 2501, resembles a “spring force” after the limit distance (IO_(LIM)) is exceeded. A second part, f₂(q_(IO)), as indicated in FIG. 29 by reference number 2502, is “slideably” added to the first part, f₁(q_(IO)), to generate a modified force versus commanded position change function, f′(q_(IO)). The second part, f₂(q_(IO)), comprises a detent 2901, which results in an abrupt change in force as shown, a parabolic section 2902, and a linear section 2903 as shown in FIG. 29. The second part, f₂(q_(IO)), is referred to as being “slideable” since the detent 2901 is centered at a position change q_(X) of the control mechanism at the time that the delay has occurred. A key feature of centering the detent 2901 in this way is that the haptic feedback on the control mechanism always exhibits a “local stiffness”

$\left( \frac{\mathbb{d}{f\left( q_{IO} \right)}}{\mathbb{d}\left( q_{IO} \right)} \right)$ which is the same at the detent regardless of where the commanded position change q_(X) of the control mechanism is at the time of the delay. In other words, the “local stiffness” that is felt on the control mechanism at the time of the delay is independent of the position of the control mechanism at the time of the delay.

The “force slope profile” of the parabolic section 2902 provides an increasing “local stiffness” on the control mechanism as the user pushes past the detent 2901. This force slope profile requires the user to apply more force to accelerate the straightening of the articulated instruments (e.g., increase the straightening velocity) as the user pushes past the detent 2901. The parabolically shaped “force slope profile” is provided in this example to compensate for the loss of sensitivity that humans normally experience as the force level increases (e.g., at high forces, humans are less good at determining small changes in force). It is to be appreciated, however, that an alternatively shaped force slope profile may be provided as long as the provided force slope profile allows the user to finely regulate the straightening velocity of the articulated instruments.

In block 2701, the method resets a counter to zero. As described below, the counter is used for determining when a delay time or count has occurred. The counter may be implemented along with the method as program code executed by the processor 43 or it may be implemented in a conventional manner as separate logic circuitry. Although a counter is described herein for determining when a delay period has occurred, it is to be appreciated that any conventional delay period determining means may be used, such as a first order low pass filter having a time constant equal to the delay period.

In block 1901, the method receives information of a commanded change in the position (q_(IO)) of the entry guide 2000 in a direction parallel to the entry guide's insertion axis X′. The commanded position change in this case is relative to the RC point, which serves as an initial position from which the change in position is determined. In one embodiment, the commanded position change (q_(IO)) may be made by the Surgeon commanding the entry guide 2000 to move along its insertion axis X′ when the system is in “entry guide” mode. In this case, however, instead of moving the entry guide 2000 along its insertion axis X′, all articulated instruments extending out of the distal end of the entry guide 2000 are to be retracted back according to the commanded position change (q_(IO)).

In block 1902, the method makes a determination whether the commanded position change (q_(IO)) is greater than a limit distance (IO_(LIM)). If the determination is NO, then the method jumps back to block 1901 to receive information of another commanded position change (q_(IO)).

On the other hand, if the determination in block 1902 is YES, then in block 2702, the method causes a haptic force “Force” to be applied against the control mechanism, which the operator uses to generate the commanded position change (q_(IO)), in a manner so as to progressively increase in force as the position change commands along the insertion axis X′ progressively exceed the limit distance (IO_(LIM)) according to a force function f₁(q_(IO)) as indicated by the function 2501 in FIG. 28. The control mechanism in this case may include one or both of the input devices 41, 42 of the Surgeon console 2102.

In block 1904, the method makes a determination whether the commanded position change (q_(IO)) is greater than a locking distance (IO_(LOCK)), wherein the locking distance is greater than the limit distance. If the determination is NO, then in block 2703, the method causes pivot joints of the entry guide manipulator (EGM) 2116 to be unlocked if they are currently soft-locked in place. The method then jumps back to block 2701 to reset the counter to zero and proceed to block 1901 to receive information of another commanded position change (q_(IO)). On the other hand, if the determination in block 1904 is YES, then in block 1905, the method causes pivot joints of the entry guide manipulator (EGM) 2116 to be soft-locked in place using their respective joint controllers.

In block 2704, the method determines whether the counter has initiated counting (i.e., whether its count is greater than zero). If the determination in block 2704 is YES, then the method proceeds to block 2705 to increment the counter while bypassing block 1906. On the other hand, if the determination in block 2704 is NO (i.e., the count is equal to zero), then in block 1906, the method determines whether the commanded position change (q_(IO)) is greater than a retraction-on distance (IO_(ON)), wherein the retraction-on distance is greater than or equal to the locking distance. If the determination in block 1906 is NO, then the method jumps back to block 1901 to receive information of another commanded position change (q_(IO)). On the other hand, if the determination in block 1906 is YES, then in block 2705, the method increments the counter. At this point, the counter has now initiated counting.

After incrementing the counter in block 2705, in block 2706, the method determines whether the count of the counter is greater than a specified count (i.e., a delay count). The specified count represents a delay that is equal to the product of the specified count and a process period for the method (i.e., the time period between each receiving of information of a commanded change in the position (q_(IO)) of the entry guide 2000 in block 1901). Both the specified count and process period may be default values programmed into the system, or either or both may be values specified by a system user through, for example, a Graphical User Interface such as GUI 2291.

If the determination in block 2706 is NO, then the method jumps back to block 1901 to receive information of another commanded position change (q_(IO)). On the other hand, if the determination in block 2706 is YES, then in block 1907, the method causes the arms (e.g., the combination of joints and links) of the articulated instruments to be straightened so as to be in proper retraction configurations while concurrently performing blocks 2707 and 2708 relative to a commanded position change (q_(X)) at the delay time (i.e., the position change being commanded at the time of the first YES determination in block 2706).

In block 2707, the method adjusts the haptic feedback force “Force” being applied against the control mechanism in block 2702 by adding on top of it the force contribution, f₂(q_(IO)), as indicated by the function 2502 in FIG. 29, so that its detent 2901 is centered on the change in position q_(X) at the time of the delay, such as shown in FIGS. 30 and 32. In block 2708, the method subjects the retractions of the articulated instruments to a progressively increasing velocity limit as the commanded position change (q_(IO)) progressively exceeds the commanded position (q_(X)) using a velocity versus commanded position change function, g(q_(IO), q_(X)), which resembles the function 2601 of FIG. 21, but shifted forward or background, such as shown in FIGS. 31 and 33, according to the difference Δ between the q_(X) and IO_(ON) commanded position changes.

Thus, as may be seen by inspection of FIGS. 30 and 31, if the user continues to push forward (in a direction of retraction towards the distal end of the entry guide), after first passing the commanded position change IO_(ON), this has the effect of moving the force detent 2901 and the velocity saturation 2601 levels forward by the difference +Δ between the q_(X) and IO_(ON) commanded position changes. As a consequence, the tool straightening feature associated to the haptic detent would be operated at slightly higher absolute force levels than in the pure position-based approach as shown in FIG. 20 (relative levels would remain undistorted though). This strategy has the beneficial effect that the straightening velocity starts at zero when the time comes (i.e., when the counter reaches the delay count), so that there is no jump in the movement of the tools. The tools start straightening as the user pushes forward from the commanded position change (q_(X)). Similar considerations hold when the user allows the tools to recoil as shown in FIGS. 32 and 33 (i.e., the user pulls back a bit after first passing the commanded position change IO_(ON). Note that in this case, this has the effect of moving the position of the force detent 2901 and the velocity saturation 2601 levels back by the difference −Δ between the q_(X) and IO_(ON) commanded position changes.

In block 1911, the method determines whether all articulated instruments previously extending out of the distal end of the entry guide 2000 are now in their retracted positions in the entry guide 2000. A retracted position in this case does not necessarily mean that the instrument is completely retracted into the entry guide 2000. As shown in FIG. 18C, for example, the articulated camera instrument 211 may still have its image capturing end exposed out of the entry guide 2000 so that it may get a better view of the surrounding area when the entry guide 2000 is being re-oriented by pivoting it about the RC point. This allows the Surgeon to view the portion of the patient anatomy where the entry guide 2000 is being re-oriented towards. Other articulated instruments may also be only partially retracted as long as their extended portions do not strike and harm the patient anatomy during the entry guide 2000 pivoting.

If the determination in block 1911 is NO, then the method jumps back to block 1901 to receive information of another commanded position change (q_(IO)). On the other hand, if the determination in block 1911 is YES, then in block 1912, the method causes pivot joints of the entry guide manipulator (EGM) 2116 to no longer be soft-locked in place by their respective joint controllers. At this point, the entry guide 2000 may be re-oriented along with all articulated instruments disposed within it and the instruments may then be extended out of the entry guide 2000 so as to be positioned to perform or continue to perform a medical procedure on the patient.

In the method of FIG. 27, if the user pulls back behind the IO_(LOCK) commanded position after exceeding the IO_(ON) commanded position, the counter will be reset per blocks 1904, 2703, and 2701. In this case, the user will have to cross the IO_(ON) threshold again in order to start the delay count again. This allows the user to correct unintentional crossings of the IO_(ON) threshold during the delay period without inadvertently initiating the straightening of the instruments in block 1907.

Also, in comparing the methods described with respect to FIG. 19 (e.g., the “position based approach”) and FIG. 27 (the “delay approach”), a useful aspect of the delay approach is that the force levels used to operate the detent may be substantially reduced as compared to the position based approach. With the position based approach, the threshold level IO_(ON) is preferably chosen to be relatively far from IO_(LIM) and IO_(LOCK) in order to avoid accidental activations. With the delay approach, the filtering action of the delay allows some reduction in the distance between IO_(ON) and IO_(LIM). Since the stiffness of the virtual spring (exhibited in the force contribution 2501) may be fixed due to system behavior considerations, moving the thresholds as described above in the delay approach advantageously allows fine tuning of the force levels.

The inclusion of a delay and its implementation may also be provided in the movement of the instrument in tandem back to the entry guide such as described in reference to FIG. 22 using the same or similar approach as described above in reference to FIGS. 27-33. Further, the application of a delayed detent function such as described above may also be applied to other mode changes in the system, such as between the tool following, imaging system, and entry guide modes.

As an example, FIG. 34 illustrates a method for switching modes of a robotic system. In block 3401, the count of a counter is reset to zero. In block 3402, the method receives an indication that a mode change has been initiated. In block 3403, the method determines whether an indication that the mode change has not been initiated is received (i.e., a contradiction to the indication received in block 3402). If the determination in block 3403 is YES, then the method jumps back to block 3401 to reset the counter and start over again in a next process cycle. On the other hand, if the determination in block 3403 is YES, then in block 3404, the method increments the counter. After incrementing the counter in block 3404, the method proceeds to block 3405 to determine whether the count of the counter is equal to a delay count. If the determination in block 3405 is NO, then the method jumps back to block 3403 to process data for the next process cycle. On the other hand, if the determination in block 3405 is YES, then in block 3406, the method applies a haptic detent on an input device or control mechanism. The method then proceeds to block 3407 and determines whether the input device has been manipulated past the detent. If the determination in block 3407 is NO, then the method jumps back to block 3406 to process data for the next process cycle. On the other hand, if the determination in block 3407 is YES, then in block 3408, the method causes the mode to be changed. Although a counter is described herein for determining when a delay period has occurred, it is to be appreciated that any conventional delay period determining means may be used, such as a first order low pass filter having a time constant equal to the delay period.

Although the various aspects of the present invention have been described with respect to a preferred embodiment, it will be understood that the invention is entitled to full protection within the full scope of the appended claims. 

What is claimed is:
 1. A method for switching modes of a robotic system, the method comprising: receiving an indication that a mode change has been initiated; providing a haptic detent on an input device after a delay following the receiving of the indication that the mode change has been initiated, the haptic detent exhibiting an abrupt reduction in a force being applied against the input device immediately before and after the delay; and changing an operating mode of a robotic system after the input device has been manipulated past the haptic detent.
 2. The method of claim 1, further comprising: initiating a counter to count to a delay count upon receiving the indication that the mode change has been initiated; resetting the counter upon receiving an indication that the mode change is not to be initiated; and determining that the delay has occurred after the counter has counted to the delay count.
 3. The method of claim 1, wherein the input device is at a first position at the end of the delay, wherein the haptic detent is followed by a force slope profile which is independent of the first position, and wherein the force slope profile exhibits a parabolic relationship between the force being applied against the input device and a change in position of the input device from the first position.
 4. The method of claim 1, wherein the robotic system has a plurality of modes including a tool following mode and an imaging system mode, the tool following mode being a mode in which the input device is operatively coupled to a tool, the imaging system mode being a mode in which the input device is operatively coupled to an imaging system, the mode change indicating that the robotic system is to change between one of the tool following mode and the imaging system mode to the other of the tool following mode and the imaging system mode.
 5. The method of claim 1, further comprising: using a first order low pass filter having a time constant equal to the delay for determining when the haptic detent is to be provided on the input device.
 6. A robotic system comprising: an input device; and a processor programmed to receive an indication that a mode change has been initiated, cause a haptic detent to be provided on the input device after a delay following the receiving of the indication that the mode change has been initiated, the haptic detent exhibiting an abrupt reduction in a force being applied against the input device immediately before and after the delay, and change an operating mode of the robotic system after the input device has been manipulated past the haptic detent.
 7. The robotic system of claim 6, wherein the processor is programmed to initiate a counter to count to a delay count upon receiving the indication that the mode change has been initiated, reset the counter upon receiving an indication that the mode change is not to be initiated, and determine that the delay has occurred after the counter has counted to the delay count.
 8. The robotic system of claim 6, wherein the input device is at a first position at the end of the delay, wherein the haptic detent is followed by a force slope profile which is independent of the first position, and wherein the force slope profile exhibits a parabolic relationship between the force being applied against the input device and a change in position of the input device from the first position.
 9. The robotic system of claim 6, wherein the robotic system has a plurality of modes including a tool following mode and an imaging system mode, the tool following mode being a mode in which the input device is operatively coupled to a tool, the imaging system mode being a mode in which the input device is operatively coupled to an imaging system, the mode change indicating that the robotic system is to change between one of the tool following mode and the imaging system mode to the other of the tool following mode and the imaging system mode.
 10. The robotic system of claim 6, further comprising: a first order low pass filter having a time constant equal to the delay for determining when the haptic detent is to be provided on the input device. 